Like every Hollywood trend of popular movies, the waters become stagnant after a while (slasher movies, teen movies, gross-out movies, etc). In theory, these movies will eventually start losing more steam at the box-office as they compete against each other. Maybe they are planning for it. In the end, it's gonna be about quality, not a big budget or expectations, for them to stand out from one another before they are put into back into Hollywood's long boxes.
I must admit in 2004, I never thought Hollywood would ever take these kinds of movies and properties seriously. I thought we were only gonna get solo Batman, Hulk, Spider-Man movies to the end of time. I gotta say in 2014 (at 38), I wish I was eight again. You can walk into any Walgreens and buy Walking Dead action figures, every Walmart has masks and toys, every channel has at least one funnybook movie or show running, and the video games!